Breadcrumb links

Services

Waste water and effluent disposal

Application forms and fact sheets

An Application to Construct or Install an Apparatus for the Treatment of Sewage must be submitted to the Shire and approval granted prior to the commencement of any installation works.

For enquiries about legislation and Guidelines contact Environmental Health Services.

Applicable legislation

Septic Tanks

Applications

Fact sheets

Most unsewered developments in Western Australia use septic tank systems to treat and dispose of sewage. These generally consist of two water tight tanks (or one large unit) and two sets of drainage receptacle e.g. leach drains or soak wells.

System installations are only permitted with local government or Department of Health approval.  The Department of Health assesses larger development proposals.  If you wish to install septic tank systems with leach drains/soakwells or an aerobic treatment unit (ATUs) you will need to lodge an Application to Construct or Install an Apparatus for the Treatment of Sewage (Link to Shire document) with the Shire.

This is to ensure that the system is of an approved design and manufacture, is properly sized and is suitably located.

It is an offence to install a wastewater system without an approval and it is also an offence to commission a system prior to a final inspection and approval to use from the local government.

Onsite treatment and disposal of effluent systems will not be approved if a property can be reasonably connected to sewer.

As they are designed to retain the solids in household wastewater, septic tank systems require routine maintenance. Pumping out the tanks on a regular basis stops accumulated fats and solids from overflowing into the drainage receptacles.

These soak wells or leach drains also need attention to ensure that the surrounding soil does not become over loaded. In systems that have been used for some time, the soil can begin to clog. Effluent is then less able to freely soak into the surrounding soil and begins to accumulate in the drainage receptacle. This can cause the effluent to surface around the drain/soak well and also back up into household pipes.

To improve the operation and longevity of drainage receptacles, new systems are now required to be alternating. This allows each section to be rested as effluent is diverted to the other leach drain or soak well area.

If you wish to manufacture septic tanks, leach drains and soakwells you need to be familiar with the requirements of the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974.

Manufacturers must apply to the Department of Health for product approval (Application for Product Approvals of Wastewater Disposal/reuse Systems) and to register their mark of distinguishing brand. Every article intended for use in the construction of an apparatus for the treatment of sewage is required to be legibly marked with the name of the manufacturer or this registered mark.

Aerobic Treatment Units

Legislation

Aerobic Treatment Units (ATUs) are a multi stage alternative to conventional septic tanks and provide an improved quality of effluent treatment. The chlorinated effluent from ATUs may be used to surface irrigate garden areas but can only be used below grassed areas. It is not approved for any use in vegetable gardens.

Due to environmental concerns, usually associated with the potential degradation of environmental water bodies, some developments are required to use a wastewater system which is capable of removing phosphates. Some ATUs are approved as Phosphate removing. These ATUs may use an in system phosphate removing process or an approved phosphate binding amended soil in the irrigation area.

The type of phosphate removing system can affect the choice of effluent irrigation methods available e.g. amended soil systems cannot be used with drippers.

Aerobic Treatment Units must be serviced regularly to ensure that they are operating effectively and that the quality of the final effluent is maintained.

The maintenance protocol is set down in the Code of Practice for the Design, Manufacture, Installation and Operation of Aerobic Treatment Units.

System installations are only permitted with Shire of Augusta Margaret River or Department of Health approval.  The Department of Health will assesses larger development proposals.

Persons wishing to install ATUs or septic tank systems need to lodge an Application to Construct or Install an Apparatus for the Treatment of Sewage with the Environmental Health unit.

It is an offence to commence construction of a wastewater system without an approval and it is also an offence to commission an illegally installed system or to commission a system prior to a final inspection and approval to use from the local government.

Composting Toilets

Composting toilets receive and treat human waste using natural decomposition processes, usually without the use of a water flush system. Some composting toilets have electric or wind driven heating/drying units to assist with the process.

A well maintained composting toilet should not smell or create a nuisance.

Wastes are retained for a sufficient period of time so that they are broken down to a safer, more stable and less offensive product. This material is not sterile and should still be handled with care.

Material from composting toilets must be buried and is not permitted to be used for the growing of fruit or vegetable plants.

Residences with composting toilets will still need a septic tank with leach drain/soakwell system or another greywater system to treat and dispose of wastewater flows from the kitchen, laundry and bathroom.  Onsite treatment and disposal of effluent systems will not be approved if a property can be reasonably connected to sewer. Composting toilets cannot be installed on lots which are less than 1000m2 in size.

As composting toilets do not remove nutrients (such as Phosphorus), they cannot be used in areas where nutrient attenuating on site wastewater disposal systems are required.

System installations are only permitted with local government or Department of Health approval.  The Department of Health assesses larger development proposals.

If you wish to install composting toilets and associated greywater systems you need to lodge an Application to Construct or Install an Apparatus for the Treatment of Sewage with the Shire.

This is to ensure that the systems are of an approved design and manufacture, are properly sized and suitably located.

It is an offence to install a wastewater system without an approval and it is also an offence to commission a system prior to a final inspection and approval to use from the local government.

Each composting toilet has a set of conditions of approval available from the Department of Health, and the manufacturer will also be able to provide information on the operation and use of their systems. Systems vary in their size and whether they approved for permanent or intermittent use.

Some composting toilets can accept food scraps in addition to human waste, as this may assist in the composting process, but not all systems can do so. 

There a two basic system arrangements. Some composting toilets are batch systems while others are of a continuous composting design. The continuous system generally has a large single chamber which waste moves through as it decomposes. They are designed to allow for a minimum detention time to allow wastes to break down before the compost is removed. They should not be overloaded.

Batch systems have more than one receiving receptacle, and more can usually be obtained if required. When the receptacles are full, they can be removed for the composting period or rotated. 

AS/NZS 1546.2:2001 Onsite domestic wastewater treatment units – Waterless composting toilets

Decommissioning of septic tanks

Legislation

When a developed property is connected to sewer, usually under the infill sewerage program, any onsite effluent disposal systems such as septic tank and leach drain/soakwell systems will eventually require decommissioning.

This means that the contents of the tank are pumped out (by an approved contractor) and the system is either removed or backfilled.

If the system can’t be removed, the tanks should still be pumped out and the bottom of the tanks can be broken up and the system backfilled with sand.

As there are costs involved in both decommissioning a septic tank and connecting to sewer, householders are not automatically required to decommission tanks when they connect to the sewer.

However under the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974 , decommissioning is required when:

  • The property is sold
  • The use of the development changes eg from a residence to a child care centre
  • Building extensions may encroach on minimums setback requirements from the system.
     

Septic tanks which have not been decommissioned should not be paved or built over without approval from the relevant local government.

Under the Code of Practice for the Reuse of Greywater in Western Australia , disused septic tank systems can be converted into the primary treatment tank for a greywater system. However, the existing drainage receptacle (e.g. soakwells or leach drains) must be replaced with an approved greywater system.

Greywater

Legislation

Applications forms and fact sheets

Greywater Product Approval Application Package

Greywater is wastewater which comes from the bath, shower, bathroom wash basins, clothes washing machine, laundry trough and kitchen sink.

Western Australia is experiencing water restrictions due to low rainfall and the critically low levels of surface water storage. Many people are interested in conserving water by reusing their greywater.  Greywater may be used via manual bucketing or an approved greywater system.

Greywater characteristics will vary according to the number of household occupants, their age, health, water use patterns and the household fixtures from which the greywater is drawn.

The Code of Practice for the Reuse of Greywater in Western Australia further explains the requirements for greywater use, and provides information on required design and performance requirements for people seeking to have new products approved.

If you are applying greywater manually, the following guidelines should be adhered to: 

  • Apply greywater in several locations to prevent pooling
  • Only bucket greywater to areas that are inaccessible to children and pets
  • Don’t use greywater from the washing of nappies or soiled clothing
  • Don’t use greywater if a member of the household has an infectious disease
  • Don’t put greywater on edible plants or fruit
  • Don’t store greywater
  • Don’t over water. Too much greywater can clog the soil, causing pooling and the development of grey/green slime areas
  • If you are installing a greywater reuse system, it needs to be of a design approved by the Department of Health and properly installed

If you wish to install a system you must lodge an Application to Construct or Install an Apparatus for the Treatment of Sewage the Shire. This is to ensure that the system is of an approved design, manufacture, and is properly sized and located.

It is an offence to install a wastewater system without an approval and it is also an offence to commission the system prior to final inspection and approval to use from the local government.

The Western Australian Government provides a rebate to help people to be more water wise by offering rebates on a variety of products, including greywater systems. Information on this can be obtained from the Department of Water website.

For more information contact:

Brad Roberts, Environmental Assistant
Hours
Mon - Fri: 8.00am to 4.30pm
Telephone
08 9780 5245
Fax
08 9757 2512

Send a message via the Contact form

RECENTLY UPDATED PAGES

Pages having content that has changed recently:

Office Hours

Margaret River

Monday to Friday: 9am-4pm

Phone inquiries: 8am-4:30pm.

Ph: +61 8 9780 5255

Augusta

Monday to Friday: 9am-Noon, 1-4pm

Phone: +61 8 9780 5660